Electric controller



March 4 1924. 1,485,542

R. E. WEIMER'ET ELECTRIC CONTROLLER Filed May 19, 1922 2 Sheets-Sheet 1 INVENTORS ATTORNEY a??? @a Q March 4 1924.

' R. E. WEIMER ET AL ELE'CTRI C CONTROLLER Filed May 19. 1922 2 Sheets-Sheet 2 Patented Mar. 4, 1924.

UNITED STATES PATENT OFFICE.

ROBERT E. WEIMER AND MATZ A. SPEIOHER, OF COLLIERS, WEST VIRGINIA, AS-

SIGNORS, BY MESNE ASSIGNMENTS, T WEIMER-WARREN COMPANY, OF COLLIERS, WEST VIRGINIA, A. CORPORATION OF WEST VIRGINIA.

ELECTRIC CONTROLLER.

Application filed May 19, 1922.

To all whom it may concern:

Be it known that we, ROBERT E. WEIMER and MATZ A. Srnror-mn, citizens of the United States, residing at Colliers, in the county of Brooke and State of West Virginia, have invented new and useful Improvements in Electric Controllers, of which the following is a specification.

Our invention relates to electric controllers.

It is the object of this invention to simplify the construction of electric controllers and to reduce their cost of manufacture.

Referring to the accompanying drawings,

Fig. 1 is a top plan view of our controller with the top of the casing removed and the operating shaft in cross-section; Fig. 2, an end view of our controller with the end of the casing removed; and Fig. 3 is a dia- V grammatic view of a motor system in which our controller is embodied.

On the drawings, 1 designates the bottom member of the casing and 2 the top or cover member thereof and 3 the rectangular body member to which the bottom and cover members are applied.

Six bolts 4 extend up through the bottom 1, three bolts being near one end thereof and three bolts being near the other end. On

:0 each bolt are strung or threaded a stack of circumferentially grooved insulator spools 5. The bottom member of each stack rests on the bottom 1, and a rectangular frame 6 rests on the top member of each stack. The

bolts 4 pass through the frame and nuts 7 are screwed down on the bolts to clamp the stack of spools 5 between the bottom '1 and the frame 6.

Three banks A, B and C of resistances are provided, each bank being composed of three separate resistance coils 8, 9 and 10, wound spirally on separate pairs of opposing stacks of spools 5. One end of each coil is secured to the bus-bar 11 and the other end of each coil is secured to the bus-bar 12, while central or intermediate point in each coil is secured to the bus-bar 13.

An insulating plate 14 is secured at its end to the sides of the frame 6 by the screws.

15. Four terminal bolts 16, 17, 18 and 19 project up through the plate 14 and are secured thereto by the nuts 20 and 21 on each bolt. The wires 22, 23, and 24 leading re- Serial No. 562,198.

spectively from the bus-bars 11, 12 and 13 are secured to the respective terminals 17, 18 and 19 by being clamped between the nuts 20 and 25 on the said terminals, the wire 24 containing the blow-out coil 26 to be described presently. The member 3 of the easing is provided with the terminals 27 28 and 29, respectively, connected by the wires 30, 31 and 32 to the terminals 16, 17 and 19.

The terminals 16, 17, 18 and 19 are arranged in the arc of a circle and have longitudinal kerfs in their outer ends to receive 65 the respective contact brushes or fingers 33, 34, 35 and 36. The lower edges of the fingers rest on the nuts 21 and their upper edges are engaged by the nuts 37 screwed on the terminals 16 to 19, whereby the fingers are adjustably clamped in the kerfs between the nuts 21 and 37. The free ends of the fingers 16to 19 are arranged in the arc of a circle and ma be engaged successively by the contact strip 38 connected to the curved edge of the half-disk 39 carried by the shaft 40 hav ing its lower end in the bracket 41 and its upper end in the cover 2. The bracket 41 is connected to the plate 14 by the screws 42. The shaft is manually operated by the handle 43 which works between the stops 44 and 45 on the cover 2. a

The positive supply line 46 is connected to the terminal 27; the shunt field winding 47, to the terminal 28 and the negative supply line 48; and the motor armature 49, to the terminal 29 and the line 48.

The blow-out magnet 26 is placed under the end of the contact finger 34 and the refractory insulating arc shields 50 are placed on opposite sides of the finger 34, their ends preferably contacting with the contact strip 38 as the latter is rotated with its carrier 39.

The parts being in the position shown in the drawings, the handle is operated to move the shaft 40, the carrier or half-disk 39 and the contact strip 38 in the direction indicated by the arrows on Figs. 1 and 3. The contact trip 38 first engages the finger 33 and next the finger 34, thereby connect ing them electrically. Current flows from the positive line 46 through the terminal 27, the wire 30, the terminal 16, the finger or brush 33, the contact strip 38, the finger or brush 3'4, and the terminal 17, from which the current branches, one branch flowing through the wire 31 and the field coil 47 to the negative supply line 48, and the other branch flowing through the bus-bar 11, the resistance coils 8, 9 and 10 in parallel, the bus-bar 12, the wire 24 and the blow-out coil 26, the terminal 19, the wire 32, the ter minal 29, and the armature 49 to the negative line 48. Under these circuit conditions the field windings 47 are fully energized and the motor armature is in series with the total resistance. After the motor current falls to what the operator regards as a safe value fo further acceleration of the motor, the handle 43 is moved another step so as to make the contact strip engage the contact finger 35, the strip then connecting the fingers 33, 34 and 35. The circuits are the same as those just traced except that the finger 35 short circuits the path between the finger 34 and the bus-bar 13, the current from the finger 33 flowing through the strip 38, the finger 35, the terminal 18, the wire 23, the bus-bar 13, the resistances between the bus-bars 13 and 12, the bus-bar 12, the wire 24 and the blowout winding 26, and thence to the negative line 48 as before. Under the new circuit conditions, the resitance between the bus-bars 11 and 13 is short-circuited and the speed of the motor is increased. When the increased motor current due to the cutting out or the resistances between the bars 11 and 13 is suitably reduced by the counter electro-motive force, the handle 43 is again moved so that the strip 38 connects all the contact fingers 33 to 36, the entire resistance and the blowout-coil being short-circuited by the finger 36, from which the current flows through the terminal 19 and thence through the armature 49 to the negative line 48 as before. The motor again speeds up and soon runs at normal speed.

The speed of the motor may be reduced by turning the handle 43 backwardly from its full on position so as to cause the strip 38 to leave the finger 36 or both fingers 36 and 35, whereby a part or all of the resistance is reinserted in the armature circuit. The motor may be stopped by turning the handle 43 backwardly until the strip 38 leaves the finger 34, which interrupts the motor circuit and causes a heavy are on the finger 34 at the place where the strip 38 breaks the circuit. This are is blown out by the magnet 26, the flash of the are being confined by the arc shields 50, the strip 38, the cover 2, and the plate 14.

It is to be noted that the blow-out winding 26 is short-circuited while the motor is in full running position, whereby some current is saved and the blow-out magnet is not needlessly heated.

When the controller is operated so as to bring the contact strip 38 into engagement with the finger 34 the field 47 becomes fully energized at nce and remains so throughout the running of the armature 49.

\Vhile the drawings show only two steps for resistance control any desired number of steps may be employed.

We claim- 1. In a rheostat for an electric motor system terminal, an armature terminal, a shunt-field winding terminal, a sectional resistance, a series of fixed contacts connected to the said field winding terminal and the sections of the resistance, a blow-out winding for the first resistance contact, a movable contact adapted to first engage the field-winding contact and then the resistance contacts in succession, the movable contact having a length suilicient to bridge all the fixed contacts, and means for short circuiting the blow-out coil when the movable contact engages a certain fixed contact beyond the first resistance contact.

2. In a rheostat for an electric motor system, spaced insulating supports arranged in pairs, a separate resistance wound spirally on each pair, means connecting corresponding ends of the resistances together, means connecting intermediate points of the resistances together, switch contacts connected respectively to the said means, the contacts connected to the ends of the resistances constituting terminals for motor leads, and a switch member cooperative with the contacts to connect the said motor terminals in circuit with all the resistances in parallel or with portions of the resistances in parallel or to connect the said motor terminals in shunt with all the resistances.

3. In a heostat for an electric motor system, spaced stacks of insulating spools arranged in pairs, a separate resistance wound spirally on each pair, means connecting corresponding ends oi the resistances together, means connecting intermediate points of the resistances together, switch contacts connected respectively to the said means, and a switch member cooperative with the contacts to connect the said motor terminals in circuit with all the resistances in parallel or with portions of the resistances in parallel or to connect the said motor terminals in shunt with all the resistances.

Signed at Colliers, W. Va., this 11th day of May, A. D. 1922.

ROBERT E. WEIMER. MATZ A. SPEICHER. 

